I don't get it either. It took me a little over 100 hours for the base game both times,first on normal then on Hard, as opposed to around 80 hours for DA:O and FO:NV, and around 50 hours for ME2 and FO3. There are around 70 side quests in the base game, some with alternative outcomes. Remember there are "wanted" boards where you can pick up long lists of bad guys to track down, and your enchanter, alchemist, etc., all give quests. I think the people who are saying they did it in around 35 hours may have missed a few things. Maybe on casual, but it's difficult to see it on higher levels. Either way, rushing through it kind of seems to defeat the purpose of an RPG.
I'm my case, I did every quest I could find, including those you mentioned, as well as a fair bit of exploration (edit: "a fair bit" meaning wandering everywhere I could find often multiple times!) I specifically dislike rushing games, so I can only guess that the quest log's counter was a bit off.
Edit 2: in fact I'm certain it is. No way did I do FoV in just 10 hours: probably over twice that.